Dual Drinking Cup

ABSTRACT

The invention provides a reversibly-attached and easily-separated set of nested cups. The outer cup can quickly and easily be detached from the inner cup, and the two cups used to share a single drink. When not in use, the outer cup remains securely attached, and provides a degree of insulation for the contents of the inner cup.

FIELD OF THE INVENTION

The present invention relates to drinking cups and, more particularly,to a cup assembly formed by the reversible nesting of two drinking cups.

BACKGROUND OF THE INVENTION

It has become a common practice to offer for sale very large soft drinkportions, with 32-ounce and even 40-ounce cups being made available toconsumers at fast-food restaurants. Souvenir cups of such sizes arecommonly sold, or included with a drink purchase, at theme parks,amusement parks, and other tourist destinations. Many consumers have nointention of drinking such a large portion, but purchase it with theintent of sharing the drink with a partner. Some consumers, however,hesitate to share a cup or a straw, or even use a separate straw in asingle drink, out of sanitary concerns. Even if that hesitation is notpresent, it is inconvenient to pass a bulky, cold, and usually wet drinkcontainer back and forth between the individuals. Few people plan theirdays so meticulously that they will be carrying with them a second cupfor use in such a situation.

The problem has attracted some attention from inventors. For example, USpatent publication No. 2002/0195451 describes a multi-sectioned cup,where different individuals are expected to drink from separatecompartments, each having its own straw. The need to pass such a devicefrom person to person remains a disadvantage.

Cups have been attached by various means to the exterior of bottles andcans; see for example U.S. Pat. Nos. 4,505,390 and 4,984,723. Such anattached cup could be used to share the contents of the can or bottle,but the disclosed means for attachment are inconvenient when dealingwith a large, wet, and not necessarily rigid cup full of liquid. Ingeneral, the prior art means for attachment involve spiral threadsrequiring several revolutions to effect disengagement of the parts, orcall upon additional parts such as handles, straps, and the like. Indealing with an inner cup full of liquid, however, where the contentsare not effectively sealed, there is a need for means of attachmentwhich permit rapid engagement and disengagement of the outer cup,without inducing large or sudden movement that might spill the contents.

There is a need for a set of mutually engaged cups, that enables acouple to share a large drink that is provided in a single cup, with theconveniences of having individual cups. Designs for such a device, whichrequires minimal force and minimizes motion of the cups during theengagement and disengagement, are accordingly provided in the presentinvention.

SUMMARY OF THE INVENTION

The present invention provides a first cup, intended to contain a drinkdispensed as a single portion by a vendor or vending apparatus. Nestedaround the bottom of the first cup is a second cup, which is affixed tothe first cup by an easily reversible means of attachment. The means ofattachment may take several forms, but in general they are molded intothe mutually facing surfaces of the cups, and are of such design as topermit disengagement of the two cups with a simple pull along the axialdirection, optionally accompanied by a short twisting motion.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a first cup of the invention, in anembodiment that features L-shaped slots in the outer surface.

FIG. 2 is a side view of the first cup of FIG. 1.

FIG. 3 is a perspective view of a second cup of the invention, in anembodiment that features four inwardly-projecting lugs on the innersurface.

FIG. 4 is a side view of the second cup of FIG. 3.

FIG. 5 is a side view of a channel with a restriction type of detent.

FIG. 6 is a top view, in cross section, of a channel with a well type ofdetent.

FIG. 7 is a side view, in cross section, of nested cups, featuringthreaded attachment means on the bottoms of the cups.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The present invention provides a first or inner cup, and a second orouter cup nested around the bottom of the first cup. The cups arefastened to one another by an easily reversible means of attachment. Themeans of attachment comprises mutually interlocking structures on theopposing surfaces of the nested cups.

The reversible means of attachment may comprises two or more lugs formedon the outer cup, the lugs being engageable with two or more channelsformed on the inner cup. The structures may be reversed, in that thelugs can be formed on the inner cup and the channels formed on the outercup. The channels optionally include detent means for reversiblydetaining the lugs, which are formed at the ends of the channels.

The reversible means of attachment may, alternatively, comprise two ormore male threads formed on one cup, the threads being engageable withtwo or more female threads formed on the other cup. Here also, the rolesof the inner and outer cup can be interchanged. Preferably, the malethreads subtend an angle of less than 180 degrees, more preferably lessthan 90 degrees, and most preferably less than 45 degrees, so as tominimize the amount of twisting required to engage and disengage the twocups. The threads will preferably have a large pitch, on the order of atleast 0.25 inches, more preferably on the order of 0.5 inches or more.In these embodiments, engagement and disengagement of the two cups is asimple matter of screwing and unscrewing them.

In an alternative embodiment, the outer cup features a threadedprotrusion on the bottom of the cup, and the inner cup features acomplimentary threaded recess on its bottom. Threading the protrusioninto the recess effects the reversible engagement of the two cups.

One preferred means of attachment is a set of projecting lugs on one cupthat engage channels in the opposing surface of the other cup. The pathof the channels on the surface may be linear, angular, spiral, or acombination thereof; in a preferred embodiment the channels areL-shaped. Each channel preferably guides an engaging lug to a detentmeans, also molded in the outer surface of the inner cup, which canreversibly trap the engaging lug. Depending upon the shape of thechannels , the two cups are readily disengaged with a simple pullingaction and/or a short twisting motion, which draws the lugs out of anydetents and out through the channels. The lugs, channels , and detentmeans are preferably molded into the surfaces of the cups duringmanufacturing.

An alternative means of attachment is an annular ridge on one cup whichengages a mating annular groove or channel on the other cup. Applicationof a light force, by hand, causes the outer cup to stretch slightly indiameter, to a degree sufficient to permit the annular ridge on one cupto enter or escape the complimentary groove on the other cup. An exampleof such a means of attachment is described in U.S. Pat. No. 4,548,348(Oct. 22, 1985 to Clements), the disclosure of which is incorporatedherein by reference for the purpose of providing an enabling descriptionof an annular ridge and a complimentary groove as reversible means ofattachment between nested cups.

Preferred means of attachment will be those which permit engagement anddisengagement of the cups without inducing large and/or sudden motionsthat would risk spilling the contents of the inner cup. Designs whichrequire minimal force and minimize motion of the cups during theengagement and disengagement are accordingly provided.

For comfort and ease of use of the outer cup, the means of attachmentare preferably located within the cup, and do not impinge on the lip ofthe cup. The means for attachment are preferably situated at a distancefrom the lip, so as not to interfere with liquid flow to and past therim. This permits the rim to be rolled out, or otherwise thickened andmade smooth and suitable for drinking.

Referring now to the drawings, where corresponding reference charactersindicate corresponding components, the inner cup of the presentinvention is exemplified by the embodiment shown in FIGS. 1 and 2, andindicated by reference character 10. The inner cup in this examplefeatures an L-shaped channel 12 for receiving a lug (22 in FIG. 3) whenthe inner cup 10 and outer cup 20 are engaged.

The cups 10 and 20 are typically of integral thermoplastic construction.In this particular embodiment, the horizontal portion of the L-shapedchannel subtends approximately twenty degrees of the circumference ofthe cup, and therefore the engagement and disengagement of the cupsinvolves only a twenty-degree rotation of the outer cup relative to theinner cup, followed by separation along the axial direction. Variationsin the length of the channel will be readily envisioned by those ofskill in the art. In general, a channel subtending less than 180 degreesis greatly preferred, so that the cups can be disengaged in a singlemotion, without the need to release either cup to re-position one'sgrip. More preferably, the angle subtended (and thus the necessaryrotation) is less than 90 degrees, and most preferably it is less than45 degrees. The channel 12 may be formed by machining or impressing, butit is most preferably molded into the outer surface of cup 10 duringmanufacture. In FIG. 4, the sidewalls of outer cup 20 are thin, so thatthe lugs give rise to visible indentations 23 on the outer surface ofthe cup.

In preferred embodiments, the channel 12 will terminate in a detentmeans 13 as shown in FIG. 2. The detent means shown in the drawings is acavity into which a lug 22 can snap into place. Referring to FIG. 5, thecavity may be defined by a necking, or restriction, 14 at the end of thechannel 12, through which the lug must be forced before entering thecavity 13 a. Alternatively, it may take the form of a well 13 bextending deeper into the surface of the cup than the channel 12, asshown in FIG. 6. In the latter embodiment, the depth of the channel willpreferably decrease as the lug approaches the detent means, so that amoderate force and accompanying deformation are required for entry ofthe lug into the well. In either embodiment, the lug 22 cannot enter orescape the detent means 13 without application of a force sufficient tocause slight deformation of the plastic, to the extent needed to forcethe lug out of the detent means. The dimensions of the detent means andlugs are chosen so that the lugs will not accidentally or inadvertentlydisengage from the detent means, yet can be intentionally disengagedupon gentle, deliberate application of force by the user.

In the embodiments shown, simply grasping the outer cup 10, and rotatingit with respect to the inner cup 20, will cause mutual deformation ofthe lugs 22 and detent means 13, sufficient to effect the release of thelugs from the detent means. The user then completes the rotation, so thelugs 22 traverse the channels 12, and separates the cups by pulling themapart axially.

FIG. 7 shows an alternative embodiment, wherein the means of attachmentare male and female threads (72 and 73, respectively) formed in thebottoms of the cups. A single-start thread is illustrated, but two ormore threads of comparable or higher pitch are alternatives that canprovide the user with more rapid engagement and disengagement of thecups. Embodiments with two-start, three-start, and four-start threadsare particularly contemplated.

Both cups may be shaped from sheets of extruded plastic material using avacuum forming process, or alternatively, one or both may bemanufactured by injection molding. Selection of an appropriate means forforming the cups, including for example injection molding orthermo-forming, will be a function of such technical considerations asthe particular polymer to be used and the intended thickness of the cup.Making such a selection is routine, and well within the abilities ofthose skilled in the art of manufacturing plastic items. The processesthemselves are well-known to those of skill in the art, and need not befurther discussed here.

The thickness of the cups' sidewalls and bottom portions are notlimited, but typically they will independently range from about 0.01inches to about 3/16 inch, depending on how sturdy and durable a cup onewishes to manufacture. Cups of the invention may be formed from any ofthe polymer resins commonly used in the art, and known to be suitablefor disposable, re-usable and souvenir drinking cups, including but notlimited to polyethylene (LDPE and HDPE), polypropylene, polyethyleneterephthalate (PET), acrylonitrile-butadiene-styrene (ABS) andpolystyrene (PS, OPS, and closed cell foam), as well as the known blendsand co-polymers thereof. Re-usable and souvenir cups can also be formedfrom aluminum or other metals, if desired, with the means for attachmentformed directly in the metal or in a polymer layer covering the metalsurface.

The inner and outer cups need not be of the same material. In certainembodiments, the outer cup will be made of an insulating, foamedplastic, and/or will feature an elastomeric surface, thereby providing adry, comfortable, and secure grip for the inner cup, when not being usedto serve a separate portion of the drink. A multi-functional outer cupof this nature can be affixed to a plastic or metal inner cup, givingthe present invention additional functionality. One of the cups may becustomized with vendor logos, team or school insignia, souvenir imagesand messages, and the like, while the other cup can be standardized andproduced in high volume at low cost. The durable and re-usableembodiments of the present invention, if adopted by vendors and madeattractive to consumers, will also reduce the volume of plastic wastecurrently being generated by the fast-food industry, and accordinglyreduce the operating costs of the vendors.

Several embodiments having been described in the present specificationand drawings, it will be recognized by those of skill in the art thatvarious modifications, alternative constructions, and equivalents may beused without departing from the spirit of the invention. The inventionis not limited to the embodiments shown in the drawings, which areintended to be illustrative and not limiting in any way.

1. A pair of nested drinking cups, consisting of an inner cup and anouter cup, the inner and outer cups each comprising a sidewall and abottom portion and being suitable for containing a drink, wherein theinner cup nests within the outer cup and is fastened to the outer cup bya reversible means of attachment, said reversible means of attachmentconsisting of either: (a) two or more lugs formed on the outer cup, thelugs being engageable with two or more channels formed on the inner cup;or (b) two or more lugs formed on the inner cup, the lugs beingengageable with two or more channels formed on the outer cup. 2.(canceled)
 3. The pair of nested cups according to claim 1, wherein thechannels further comprise detent means for reversibly detaining thelugs. 4-20. (canceled)